Electrically operated displacement pump control system and method

Patent metadata

Field	Value
Publication number	US-12092090-B2
Application number	US-202318133840-A
Country	US
Kind code	B2
Filing date	Apr 12, 2023
Priority date	Mar 31, 2020
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

An electrically operated displacement pump includes an electric motor having a stator and a rotor. The rotor is connected to the fluid displacement member to drive axial reciprocation of the fluid displacement member. A drive mechanism is disposed between and connected to each of the rotor and the fluid displacement member. The drive mechanism receives a rotational output from the rotor and provides a linear input to the fluid displacement member. A controller controls operation of the motor based on an operating state of the motor to control pumping by the displacement pump.

First claim

The invention claimed is:

1. A pump for pumping a fluid, the pump comprising:
an electric motor comprising a stator and a rotor, the rotor configured to generate rotational output on a pump axis;
a first fluid displacer connected to the rotor such that the rotational output from the rotor moves the first fluid displacer to pump the fluid;
a user interface configured to receive a parameter output setting from a user, the parameter output setting corresponding to a target output parameter for the fluid output by the pump; and
a controller configured to regulate current flow to the electric motor, wherein:
the controller is configured to receive the parameter output setting and regulate current to the electric motor based on the parameter output setting;
the controller regulates output of the fluid by regulating the current flow to the electric motor such that the rotor rotates to cause the first fluid displacer to pump the fluid until a pressure of the fluid stalls the rotor even while the current is supplied to the electric motor by the controller so that the rotor applies torque while the rotor remains stalled, the first fluid displacer configured to resume pumping when the pressure of the fluid drops enough for the rotor to overcome the stall and resume rotating; and
wherein the controller is configured to provide a first power signal having a first waveform to the electric motor while the rotor is rotating and is configured to provide a second power signal having a second waveform to the electric motor while the rotor is stalled such that the controller switches from delivering the first waveform during pumping to delivering the second waveform during rotor stall, the first waveform different from the second waveform.

2. The pump of claim 1 , wherein the target output parameter is a target pressure and the parameter output setting is a pressure output setting such that the controller is configured to receive the pressure output setting for the pump from the user, the pressure output setting corresponding to a current level at which the controller supplies the current to the electric motor.

3. The pump of claim 2 , wherein the pressure output setting is configured to correspond to a maximum speed of the pump.

4. The pump of claim 1 , wherein the parameter output setting is generated based on a single input to the user interface of the pump.

5. The pump of claim 1 , wherein the pump does not include a pressure transducer that influences a level of power supplied by the controller to the electric motor.

6. The pump of claim 1 , wherein the controller is configured to regulate the current flow to the electric motor based on data other than pressure information from a pressure transducer.

7. The pump of claim 1 , wherein the controller is configured to operate the electric motor in a start-up mode and a pumping mode, wherein during the start-up mode the controller is configured to:
cause the electric motor to drive the first fluid displacer in a first direction along the pump axis; and
determine an axial location of the first fluid displacer based on the controller detecting a first current spike when the fluid displacer encounters a first stop.

8. The pump of claim 1 , wherein the electric motor comprises a first phase, and the controller is configured to provide the first power signal having the first waveform to the first phase while the rotor is rotating and is configured to provide the second power signal having the second waveform to the first phase while the rotor is stalled.

9. The pump of claim 1 , wherein the first power signal is sinusoidal and the second power signal is constant.

10. The pump of claim 1 , wherein the first power signal is an alternating current signal and the second power signal is a direct current signal.

11. The pump of claim 1 , wherein the controller is configured to pulse the flow of current in the stalled state so that the rotor outputs varying amounts of torque.

12. The pump of claim 1 , wherein the controller regulates the current flow to the electric motor such that the rotor stall occurs when the fluid output reaches the target output parameter.

13. The pump of claim 1 , wherein the first fluid displacer is disposed coaxially with the rotor.

14. The pump of claim 1 , wherein the first fluid displacer is configured to reciprocate on the pump axis to pump the fluid.

15. A method of operating a reciprocating pump to pump a fluid, the method comprising:
receiving, by a controller, a parameter output setting from a user, the parameter output setting corresponding to a target output parameter for the fluid output by the pump, wherein the controller is configured to regulate current to an electric motor based on the parameter output setting;
electromagnetically applying a rotational force to a rotor of the electric motor;
outputting, by the rotor, a rotational output to move a first fluid displacer to cause the fluid displacer to pump the fluid; and
regulating, by the controller, a flow of the current to a stator of the electric motor such that the rotational force is applied to the rotor during both a pumping state and a stalled state, wherein regulating comprises delivering the flow of current to the electric motor to move the first fluid displacer to pump the fluid until a pressure of the fluid stalls the rotor while current is supplied to the electric motor by the controller so that the rotor applies torque while the rotor remains stalled, and the first fluid displacer resumes pumping when the pressure of the fluid drops enough for the rotor to overcome the stall and resume rotating;
wherein the controller provides a first power signal having a first waveform to the electric motor while the rotor is rotating and provides a second power signal having a second waveform to the electric motor while the rotor remains stalled such that the controller switches from delivering the first waveform during pumping to delivering the second waveform during rotor stall, the first waveform different from the second waveform;
wherein, in the pumping state the rotor rotates about a pump axis causing the first fluid displacer to move coaxially with the rotor to apply force to the fluid; and
wherein in the stalled state, the rotor applies torque and does not rotate about the pump axis such that the first fluid displacer applies force to the fluid and does not move.

16. The method of claim 15 , wherein regulating, by the controller, the flow of current to the stator includes:
pulsing the current in the stalled state such that the rotor applies varying amounts of torque when in the stalled state.

17. The method of claim 15 , further comprising:
determining, by the controller, that the pump is in the pumping state based on a sensor detecting rotation of the rotor.

18. The method of claim 15 , further comprising:
regulating, by the controller, a rotational speed of the rotor such that the rotational speed is at or below a maximum speed; and
regulating, by the controller, current provided to the electric motor such that the current provided is at or below a maximum current.

19. The method of claim 15 , wherein the first power signal is sinusoidal and the second power signal is constant.

20. The method of claim 15 , wherein the first power signal is an alternating current signal and the second power signal is a direct current signal.

Assignees

• Graco Minnesota Inc

Inventors

• Hines Bradley H
• Scheierl Paul W
• Koehn Brian W
• Higgins Jacob D
• Paar Benjamin J
• Fehr David L

Classifications

• F04B49/14

  Adjusting abutments located in the path of reciprocation · CPC title

• F04B49/02

  Stopping, starting, unloading or idling control · CPC title

• F04B17/03 Primary

  driven by electric motors · CPC title

• F04B43/04 Primary

  Pumps having electric drive · CPC title

• F04B49/065

  and making use of computers · CPC title